The field of this invention is teleconferencing, and particularly teleconferencing using an internetwork comprising a connection-oriented and a connectionless network.
Teleconferencing is carried out by certain known systems using a connection-oriented network or internetwork. An internetwork is defined as a set of networks that are directly or indirectly interconnected. The most prevalent example of a connection-oriented network is the Public Switched Telephone Network (PSTN). As shown in FIG. 1, teleconferences on the PSTN 11 are established in a known fashion in one embodiment by a PSTN teleconference bridge 12 that has been preconfigured to establish the teleconference, e.g., with certain participants 13, at a certain time, etc. In one embodiment, one of the participants 13 preconfigures the bridge 12. In another embodiment, a teleconference administrator 14 preconfigures the bridge 12. In one embodiment, the bridge 21 calls the predetermined participants 13 and authenticates them. In another embodiment, the participants 13 call the bridge 12 and authenticate themselves. An example of an authentication mechanism is the entry of a password using Dual Tone Multi Frequency (DTMF) signals at a prerecorded audio prompt from the bridge 12. The bridge 12 bridges the authenticated connections, enabling the participants 13 to communicate with each other. A teleconference over a connection-oriented network such as the PSTN offers high quality, low latency multimedia transmission and reliable connections. Multimedia is defined to be information of the form of at least one of the group of audio, text, video, animation and graphics. Latency is defined to be the delay between the time information is sent and time it is received. A connection-oriented teleconference connection can be disadvantageously expensive, and does not readily offer the caller a multimedia interface useful for controlling and monitoring the status of the teleconference that is easily accessed using any of a number of general purpose software packages implemented on a wide variety of hardware platforms and networks. A useful teleconferencing multimedia interface would provide information such as the availability of teleconferences for which a user is scheduled or free to join; information on the status of a teleconference (e.g., the identities of the participants, whether a participant""s connection is presently active or has been dropped, etc.); and means for conveniently scheduling and establishing a teleconference.
Other known systems carry out teleconferences using a connectionless network. An example of a connectionless network is the Internet. As shown in FIG. 2, participants or users 21 establish TCP/IP connections with a teleconference server 22 through the Internet 23, are authenticated, and send digitized connectionless voice signals in packets to the server 22. The teleconference server 22 multiplexes the connectionless voice input signals from the participants 21 and sends the resulting multiplexed signal to the participants 21 through the Internet 23. The server 22 can be preconfigured to host a teleconference consisting of certain predetermined participants, at a scheduled time, etc. The server 22 can be preconfigured by participants 21, or by a third party such as a teleconference administrator 24. Multimedia teleconferences over the Internet are inexpensive and can be established and monitored using convenient multimedia interfaces presented to the participants 21 and/or a third party such as teleconference administrator 24. An example of such a multimedia interface presents graphical and textual information to the participant, augmented by audio, video and animation. However, multimedia teleconference connections can be disadvantageously unreliable, suffer from high latency, and have high data error rates.
Using known systems, connection-oriented conferees (conferees communicating over a connection-oriented network) may teleconference only with other connection-oriented conferees, and connectionless conferees (conferees communicating over a connectionless network) may teleconference only with other connectionless conferees. Connection-oriented conferees often need to teleconference with connectionless conferees, and vice versa. Known systems are unable to accommodate such a hybrid mix of conferees, and hence the two groups are unable to communicate together.
An apparatus is provided for teleconferencing on an internetwork that has a connection-oriented network connecting a caller to a bridge and a connectionless network connecting users. A call server is connected to both the connection-oriented network and the connectionless network. The call server receives connectionless input signals from users through the connectionless network, multiplexes the signals, and translates the multiplexed signal into a connection-oriented output signal. The output signal is sent to the bridge connected to the connection-oriented network, which shares the signal with connection-oriented users. The call server receives a connection oriented input signal from the bridge, translates the connection oriented signal into connectionless output signal, and sends the connectionless signal to the users on the connectionless network. Thus, both connectionless and connection-oriented conferees can advantageously participate in the same teleconference. The call server accepts connectionless teleconference identification data from users, as well as caller authentication data, and provides both to the bridge. The call server further advantageously monitors the status of connectionless users and the connection to the bridge, and provides control signals and information both to the bridge through means such as DTMF signals and to the users through multimedia interfaces.